Officers who responded to the shooting of Cold Spring police officer Thomas Decker outside a bar last week were confused about whether to allow bar patrons to leave and where to set up a perimeter, according to an audio recording of the dispatch and an interview with a bar patron.

The dispatch recording obtained by MPR News begins with a call from a police officer, "Shots fired, officer down." A few seconds later, he adds, "I have no idea where the suspect went."

The recordings provide a glimpse into the first minutes of an investigation that, more than a week later, has failed to find a gun or Decker's killer. Police arrested a man who lived above the bar, Ryan Larson, Thursday night, but he was released on Tuesday after prosecutors said they did not have enough evidence to file charges. Larson has denied killing Decker and said he was asleep when the shooting occurred.

Police have released few details about what happened the night Decker was killed. At a news conference last Friday, law enforcement officials said Decker was shot when he stopped to check on Larson, who lives in an apartment above Winner's Sports Bar & Grill. Law enforcement officials said Larson's family called the Stearns County Sheriff's Office at about 9 p.m. and said they were worried Larson might be suicidal. Officers went to Larson's apartment, but did not make contact with him. Decker and another officer went back to his apartment an hour and 45 minutes later to try to find him, according to Stearns County Sheriff John Sanner.

"Decker left his squad car and a very short time later was confronted by an armed individual, shot twice, and died," Sanner said at the Nov. 30 news conference.

Law enforcement officials have declined to identify the officer on duty with Decker that night. They also declined to say whether Decker fired his gun, where he was hit, whether his partner was in a squad car during the shooting, and what his partner did after the shooting.

The audio recordings of the dispatch calls provide new information about the initial response to the shooting. The recordings indicate that additional officers arrived at the scene within a few minutes. About five minutes after the initial call, someone says, "It appears a gunshot wound to the head."

Cold Spring shootingAP Photo/The St. Cloud Times, Eric Stromgren

Three minutes later, an officer says, "We're going to see if there's anybody else inside the bar. There's a bunch of people standing outside. I told them to leave at this point."

A few seconds later, someone advises that bar patrons provide identification to police officers outside. The bar patrons should "walk out with their hands up," one person advises.

"Everybody filed out through the door and once you got outside it seemed like there were a hundred cops, " said Roger Binsfeld, one of the people in the bar at the time. "Realistically there was probably 20 of them. They all had their guns drawn. Assault rifles. Pistols. All pointed at us. Because they didn't know if the guy who shot the cop went inside, or where he was."

Binsfeld estimates there were 30 people in the bar at the time of the shooting, but he says no one seems to have heard the shotgun blasts over the sound of the conversation and jukebox.

He said people in the bar first became aware of the dead police officer after another patron went to retrieve a cell phone from a car saw Decker on the ground in the bar's parking lot. A bartender who went to check returned a short time later and told the others in the bar she thought the officer was dead.

Larson, the man who would later be arrested on suspicion of killing Decker, is first mentioned by someone on the dispatch line about two and a half minutes after the initial call. The audio is filled with static, but a woman can be heard saying, "suicidal male Ryan Larson." A description of Larson follows, but there is no indication that anyone initially considers Larson a suspect, although dispatch recordings offer only one perspective of the investigation.

About 17 minutes after the first call, someone says, "he lives above the bar, suicidal before." A few seconds later, someone says, "The scene is secure."

However, officers did not know the exact boundaries of the secure perimeter around the scene for at least a half-hour. "To all units, give a call out where your location is on the perimeter so we can log it in, so I can look to make sure I have all corners covered," someone says.

A woman on the dispatch line cautions, "You maybe should be doubled up, two people, doubled up, watch each other's backs."

The dispatch calls refer to several other possible leads, including specific vehicles driving on nearby roads and a "black male leaving the area shortly after the shooting." At one point, someone says, "Suspect had a handgun."

Twenty-five minutes after the initial call, paramedics confirm that Decker has died.

On Wednesday night, Minneapolis police officers raided a known drug house in the 2800 block of 14th Ave. South, in connection to the Cold Spring case, according to the Star Tribune. Minneapolis police spokesperson William Palmer confirmed the police raid, but did not say whether it was connected to the Cold Spring shooting. He said the Bureau of Criminal Apprehension, the agency leading the Cold Spring investigation, took one person into custody.

Police in downtown Cold Spring, Minn. Friday morning, Nov. 30, 2012, following a Thursday night shooting that killed one officer. Cold Spring is southwest of St. Cloud.MPR Photo/Conrad WilsonView full galleryOfficer Tom Decker, 31, and another officer responded to a call about a potential suicide in an apartment above Winners Sports Bar and Grill on Main Street in Cold Spring, Minn. when Decker was ambushed and shot behind the bar late on Thursday, Nov. 29, 2012.MPR Photo/Tim NelsonIn a Monday, Dec. 3, 2012 photo, People gather for a vigil for Cold Spring Police Officer Tom Decker in the parking lot of the Wenner Funeral Home in Cold Spring, Minn. Decker, 31, was fatally shot Nov. 29 when he and his partner were checking on a report of a man believed to be suicidal.AP Photo/The St. Cloud Times, Jason WachterThe children and first wife of Cold Spring police officer Tom Decker gather in their Sartell home Saturday, Dec. 1, 2012. Pictured are mother Becky Decker, and children, from left to right, Jade, Devon, Kelly and Justin. Richmond Police Officer Tom Decker, 31, was killed late Thursday, Nov. 29 in what police say was an ambush near Winner's Bar in Cold Spring.AP Photo/The St. Cloud Times, Dave SchwarzOfficers walk to the funeral of Cold Spring police officer Thomas Decker at St. John's Abbey and University Church on the campus of St. John's University in Collegeville, Minn. Wednesday, Dec. 5, 2012.Jeffrey Thompson/MPR Photo/Jeffrey ThompsonThe casket of Cold Spring police officer Thomas Decker is brought out of St. John's Abbey and University Church on the campus of St. John's University following Decker's funeral in Collegeville, Minn. Wednesday, Dec. 5, 2012.MPR Photo/Jeffrey ThompsonStudents from ROCORI school in Cold Spring, Minn. greet a procession of police and safety vehicles following Cold Spring police officer Thomas Decker's funeral Wednesday, Dec. 5, 2012.MPR Photo/Jeffrey ThompsonOnlookers in Cold Spring on December 5, 2012 waited for Officer Tom Decker's casket to pass. Decker's funeral was Wednesday. He was shot and killed while responding to concerns about a possible suicidal man.MPR photo/Conrad Wilson